Switching apparatus



Nov. 6 1923. 1,473,386

w. M. SCOTT SWITCHING APPARATUS Original Filed Nov. 26, 1919 2 Sheets-Sheet 1 INVENTO 4 ATTORNEY Patented Nov. 6, 1923.

UNITED STATES PATENT DFFICE.

SWITCHING APPARATUS.

Applicationflled November 26, 1919, Serial No. 340,724. Renewed October 12, 1922. Serial No. 594,199.

To all whom it may concern Be it known that I, \VILLIAM M. Scorer, a citizen of the United States, residing in Tredyfl'rin Townshi in the county of (hester and State of ennsylvania, have invented anew and useful Switching Apparatus, of which the following is a specification.

My invention relates to electrical switch or circuit breaker structure utilizable for controlling or protecting electric circuits carrying current for power, lighting or other purposes.

More particularly my invention relates to electric switch or circuit breaker structure of the character disclosed in my prior application Ser. No. 328,056, filed October 2. 1919.

' My invention resides in operating mechanism for an electric switch or circuit breaker, and more particularly for a plurality of switches or circuit breakers which coact with the same or different circuits and particularly such as shall be alternately, and not simultaneously, operated.

My invention resides in operating mechanism of the character referred to associated with switch or circuit breaker mechanism enclosed within a box or other housing preventing access to the switch or circuit breaker mechanism, its actuation being accomplished by said operating mechanism from the exterior of the box or housing.

My invention resides also in means for indicating to the exterior of the'housing the position of the switch or circuit breaker mechanism.

For an illustration of one of the various forms my invention may take, reference is to be had to the accompanying drawingain which:

Fig. 1 is a side elevational view of apparatus embodying my invention, walls of the housing structure being broken away.

Fig. 2 is a front elevational view of the structure shown in Fig. 1, with part of the housing cover broken away.

Fig. 3 is a fragmentary view of part of the operating mechanism.

Fig. 4 is a section, on larger scale. on line 4-4 of Fig. 3.

Fig. 5 is a fragmentary view of theoperatin mechanism.

Fig. 6 is a fragmentary side elerational view of the indicating mechanism.

Fig. 7 is a front elevational view of the indicating mechanism.

Fig. 8 is a side elevational view of the same. 1

Referring to the drawings, 1 is a base of insulating material, as of slate or the like. secured in vertical position by screws 2 to a metal box or housing 3 adapted to be secured to a wall or pillar of a building, or any other suitable support. Secured upon the front of the base 1 is the switch or circuit breaker mechanism about to be described housed in the box or other suitable housing 4 secured to the base 1 by screws 5 engaging in angle or other structural pieces 6 to which the box walls are secured. The front wall of the box is the door or cover 7 pivoted at its upper edge at 8 and locked in closed position indicated by padlock or the like, not shown, passing through the aperture 9 in the stud 10 secured to the box structure and extending through an aperture in the door 7.

The switching mechanism comprises two switches or circuit breakers A and B disposed side by side upon the base 1 as indicated in Fig. 2. They are or may be essentially the same in structure, and a description of one will suflice for a description of the other.

Each comprises the stationary main terminals 11 and 12 secured upon the front face of the base 1 by the studs 13 and 1% upon which are threaded the nuts 15 and 16. Between nuts 15 is clamped a conductor or cable terminal 17, the two terminals 17 of the two breakers A and B connecting. respectively, with the insulated conductors 18 and 18", which may be enclosed in the conduit or pipe 19 extending through an aperture in the housing 3 whose wall adjacent the aperture is clamped between the nuts 20 and 21 threaded upon the conduit 19.

Through an aperture in the lower end of the box 3 extends a similar conduit 22 similarly held'by nuts 23 and 24 threaded thereon. Extending through the conduit 22 are the insulated conductors and 25", of which 25 connects to the terminal 26 secured between the nuts 27 threaded upon the stud 28 which extends through the base 1 and threads into a block 29 with which connects the conductor 30 connecting to one terminal of the electro-magnet winding 31 whose other terminal connects with the terminal 12 of the breaker mechanism A, the stud 14 and terminal 12 of the breaker A having no direct connection to the exterior of the box 3, but the indirect connection through the aforesaid winding 31 and conductor 25. The conductor 25 connects with the terminal 32 held between the nuts 16 upon the stud 14 of the breaker B.

Each breaker mechanism comprises the laminated bridging member 33 engaging and bridging the upper and lower contacts 11 and 12. Accordingly it will be understood that the path through the breaker mechanism A is from conductor 18, its terminal 17, stud 13, terminal 11, bridging member 33, and lower terminal 12, thence through magnet winding 31, conductor 30, block 29, stud 28, terminal 26 and conductor 25. The path through breaker B is from conductor 18", its terminal 17, stud 13, terminal 11, bridging member 33. lower terminal 12, and thence through its stud 14, to terminal 32 and conductor 25".

The conductors 18 and 18 may be considered the supply conductors of an electric circuit, while the conductors 25 and 25 are those of the consumption circuit, the switching mechanism therefore comprising a double pole circuit breaker mechanism.

Each of the bridging members 33 is cured upon an arm 34 pivoted at 35 to a bracket 35 secured upon the base 1. Pivoted to the same bracket at 36 is the toggle link 37 pivoted at 38 to the toggle arm 39 pivoted at 40 to arm 34. 1Vith the bridging 1nem-.

ber 33 in circuit closing position illustrated the center of the pivot 40 is slightly below the imaginary line joining the centers of pivots 36 and 38, and the toggle structure is under-travelled. The structure is held in circuit closing position shown by the latch 41 pivoted to the bracket 35 and capable of pivotal movement concentric with the pivot 35, and engaging a roller pivoted at 42 upon the toggle arm 39. The tail 43 of latch 41 is adapted to be engaged by the latch actuator 44 to disengage the latch 41 from the member 39. The latch 41 may also be actuated by the pin 45 actuated by the manual tripping member 46 pivoted concentrically with the pivot 35, the pin 45' engaging loosely in a slot in the latch 41.

The latch actuators 44 of the breaker mechanisms are connected to the trans versely extending bar 47 secured by screw 48 upon the armature 49 of the electro-magnet whose winding is the aforesaid coil 31 disposed upon the core 50 having the pole pieces 51. The armature 49 is adjustable as to its distance from the pole pieces 51 by the screw 49, for causing response to different magnitudes of current.

The armature 49 carries a pin 52 disposed in an elongated slot in the upper end of the link 53 pivoted at 54 to the member 55 pivoted to a stationary bracket at 56 and having secured thereto the downwardly extending arm 57 in the path of travel of the plunger 58, held retracted by spring 59 and adapted to be actuated in opposition to said spring by the push button 60 upon the rod 61 abutting against the plunger member 58, manually to trip the latches 41, or either of them, from outside of the housing structure.

To each of the toggle arms 39 is secured a member 62 forming therewith an operating arm or lever for the breaker mechanism, and carrying near its extremity the pivot pin 63.

Having bearings 64 in the side walls of the box 4 is the horizontally extending rock shaft 65 upon whose outer end is secured by pin 65 the hand crank 66 having the handle 67 which may be locked in the position indi cated by a padlock, not shown, whose looking member extends around the crank 66 and through the aperture 68 in the In 69 secured to a wall of the box 4.

Surrounding the shaft 65 is the tube '70 forced to rotate with the shaft 65 by the pin 71, Fig. 2, engaging in a notch in one end of the tube 70 and secured to the shaft 65.

To the pin 63 of operating lever 62 of breaker A is pivoted a link 72 having at its lower end a slot 72 embracing a pivot pin '73 carried at one end of the link 74 extending through a slot 75 in tube 70 and having at its'lower end a 1101c through which the shaft 65 loosely extends.

Similarly, to the pivot pin 63 of lever arm 62 of breaker B is pivoted the link 76 having slot 76 in which is disposed the pivot pin 77 on the link 78 extending through a slot 79 in the tube 70 and having a hole at its lower end through which loosely extends the shaft 65.

As shown in Figs. 1 and 5, the pair of links 72, 74 is symmetrical with respect to the pair 76, 78, the two pairs being disposedon opposite sides of an imaginary line passing through the centers of shaft 65 and pivot 63, and operable and operative in opposite directions as regards rotary movement about the shaft 65.

WVith the parts in the circuit closing position indicated, upon occurrence of overload the armature 49 will be attracted by the electro-magnet whose winding is 31 and will cause the latches 41 of both breaker mechanisms to be actuated, thereby releasing the members 39 and allowing movement of the contact members 33, under influence of s rings usual in circuit breakers, away from tlie terminals 11 and 12 by clockwise rotation about the pivots 35, the final break, as well understood in the art, taking place at the shunt carbon contacts 33* and 33". This movement from circuit closing to circuit rupturing position is accompanied by movement of the link structures, Figs. 1 and 5, from the position indicated in dotted lines in Fig. 5 to the posit-ion indicated in full lines, the link 7 4 rotating in counterclockwise direction and link 78 in clockwise direction during the opening movement. The links 7 4 and 78 rotate freely upon the shaft 65 and move freely through the circumferentially incomplete slots 75 and 79 in the tube 70,

without movement of tube or shaft 65.

Resetting of the circuit breakers A. and

B can be accomplished only alternately;

. their simultaneous reclosure or resetting is not possible, and this is the desired action, since it is the purpose of the particular example of application of my invention illustrated to afford the so-called double-arm effect in that upon existence of an overload condition upon the circuit one arm may be closed, but upon closure of the other arm the arm first closed or both arms are tripped to open circuit position, so in effect preventing closure of the circuit during the continuance of an overload or any other undesired circuit condition.

To reset or reclose the circuit breakers the hand crank 66 is turned first in one direction from its normal position indicated to close one of the breakers, and then in opposite direction to close the other, the handle 66 returning to normal position indicated due to gravity, or by spring biasing means if desired. 7

Amuming both breakers open, the breaker A may first be closed by rotating the hand crank 66 in clockwise direction, as viewed in Figs. 1 and 5, thereby rotating the shaft 65 and tube 70 in like direction until one end of the slot presses upon one side of i the link 74, rotating it in clockwise direction, pulling down upon the actuating arm 62 through line 72, the rotat-ive movement of the crank 66 being continued until breaker A attains circuit closing position and is there retained by reen agement of latch 41 with the member 39. hiring this resetting movement the links 78 and 76 remain stationary because of the disposition of the slot 79 such that during closing movement of breaker A the end of slot 79 does not engage link 78. Upon closure of the breaker A the hand crank 66is moved in counterclockwise direction through and beyond its normal position until one end of the slot 79 engages the link 78, rotating it in counterclockwise direction pulling down on link 76 and rotating the operating arm 62 of breaker B, bringing it to circuit closing position, wherein it is locked by engagement of its latch 41 with its member 39. Upon release of the handle 67 the hand crank 66 will return under influenceof gravity to vertical position indicated, the shaft 65 and tube 70 simultaneously rotating therewith to normal position.

Lugs 80 and 81 are disposed upon the outer wall of the box 4 in the path of travel of the hand crank 66, lug 80 limiting its clockwise movement and lug 81 its counterclockwise movement, as viewed in Fig. 1.

The disposition of the pairs of links cooperating with the shaft 65 and tube 70 is such that it requires movement of the shaft 65 in opposite directions to effect closures of their associated breaker mechanisms; and the circumferential extents of slots 75 and 70 are such that they permit of free movement of the tube 7 0 without actuating one of the breaking mechanisms while closing the other; and the slots 75 and 79 are further so displaced angularly with respect to each other that the afore-mentioned actuation of the breaker mechanisms is possible.

\Vith each breaker mechanism may be associated means for indicating, without opening door 7, whether it is in the open or closed position. a

In the door 7 there is associated with each breaker mechanism an aperture 82, Fig. 2, through which is visible the front face 83, Fig. 8, of the vertically sliding member 84 having vertically extending slots 85 through which extend the pins 86 carried on the inner face of the door 7 To the upper pin 86 is connected one end of the tension spring 87 whose lower end is attached to the inwardly extending horizontal lug 88 on member 84, the spring tending to hold the member 84 in its uppermost position indicated in Fig. 7. Extending horizontally inward is a lug 89 secured upon the inner face of the member 84 and extending into the path of travel of the pivot pin 63 of the breaker operating arm 62.

When the circuit breaker is open the member 84 is in its uppermost position, and there is visible upon its front face 83 through the aperture 82 in door 7 that portion of the face 83 which may be suitably marked, as by White coloring material, and thereby indicate that the breaker is open. In closing the breaker the pin 63 descends and engages the upper edge of the lug 89. forcing the member 84 to slide downwardly in opposition to spring 87 and bring a new portion of the face 83 into register with the opening 82, such portion being colored, for example, in red, to indicate that the breaker mechanism is now in closed position. Upon tripping of the breaker the spring 87 returns the member 84 to its uppermost position.

As indicated in Fig. 6, if a breaker should be in circuit closing position and the door T open, and it be attempted to close the door,

the vertical edge 90 of the lug 89 will engage the pin 63 and so hold the door 7 open or pre vent its closure, until the breaker is tripped or moved to open circuit position. lVhen both breakers are in open circuit position the door may readily be closed and locked, and thereafter the breakers may be closed by the operation hereinbefore described.

What I claim is:

1. The combination with the movable member of a switch, of oscillatory link structure connected therewith, and a rotatable slotted member into and within which said link structure extends and is pivoted, said member engaging at the end of its slot with said link structure for actuating the same.

2. The combination with the movable member of a switch, of oscillatory link structure connected therewith, a rotatable slotted member into and within which said link structure extends and is pivoted, said member engaging at the end of its slot with said link structure for actuating the same, an enclosing housing, and means external thereto for actuating said member.

3. The combination with the movable member of a switch, of oscillatory link structure connected therewith, a. rotatable slotted member into and within which said link structure extends and is pivoted, said member engaging at the end of its slot with said link structure for actuating the same, an en closing housing, means external thereto for actuating said member, and means for limiting the extent of movement of said means.

4. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, and a rotatable member having slots into and within which said links extend and are pivoted, said member at the end of each slot engaging the link therein for actuating the same.

5. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, a rotatable member having slots into and within which said-links extend and are pivoted, said member at the end of each slot engaging the link therein for actuating the same, an enclosing housing, and means external thereto for actuating said member.

6. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, a rotatable member having slots into and within which said links extend and are pivoted, said member at the end of each slot engaging the link therein for actuating the same, an enclosing housing, means external thereto for actuating said member, and

means for limiting the extent of movement of said means.

7. The combination with a pluralit of independently operable switches eac comprising a movable contact member, a link and connections therewith and said contact member, said links rotatable in opposite directions for actuating said contact members in similar directions, and a rotatable memher having slots into and within whichsaid links extend and are pivoted, said member at the ends of said slots engaging said links for actuating the same in opposite directions.

8. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, said links rotatable in opposite directions for actuating said contact members in similar directions, a rotatable member having slots into and within which said links extend and are pivoted, said member at the ends of said slots engaging said links for actuating the same in opposite directions, an enclosing housing, and means external thereto for actuating said member.

9. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, said links rotatable in opposite direc tions for actuating said contact members in similar directions, a rotatable member having slots into and with-in which said links extend and are pivoted, said member at the ends of said slots engaging said links for actuating the same in opposite directions, an enclosing housing, means external thereto for actuating said member, and means for limiting the extent of movement of said means.

10. The combination with a plurality of independently operabl switches each comprising-a movable contact member, a link and connections therewith and said contact member, of a shaft upon which said links are pivoted, and a tubular member enclosing said shaft and rotatable therewith and having slots intowhich said links extend, said tubular member at the ends of said slots adapted to engag said links for actuating the same.

11. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, of a shaft upon which said links are pivoted, a tubular member enclosing said shaft and rotatable therewith and having slots into which said links extend, said tubular member at the ends of said slots adapted to engage said links for actuating the same, and means for actuating said shaft.

12. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, of a shaft upon which said links are pivoted, a tubular member enclosing said shaft and rotatable therewith and havin slots into which said links extend, said tu ular member at the ends of said slots adapted to engage said links for actuating the same, means for actuating said shaft, and means limiting the extent of movement of said means.

13. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact mem-' her, said links movable in opposite directions for effecting movement of said contact members in similar directions, a shaft upon which said links are pivoted, and a tubular member enclosing said shaft and having slots into which said links extend, said tubular member at ends of said slots adapted to engage said links for actuating them in opposite directions.

14. The combination with a plurality of independently operable switches each comprising a movable contact member, a link and connections therewith and said contact member, said links movable in opposite directions for effecting movement of said contact members in similar directions, a shaft upon which said links are pivoted, a tubular member enclosing said shaft and having slots into which said links extend, said tubular member at ends of said slots adapted to engage said links for actuating them in opposite directions, and means for rocking said shafts in opposite directions for alternately actuating said contact members.

15. The combination with a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means for restraining each of said contact members in normal position, tripping mechanism for disengaging said contact members from said restrainin means, means for alternately actuating said contact members to normal position comprising an oscillatory member concentric with which said links are pivoted, and shoulders on said oscillatory member for engaging said links for actuating them in opposite directions.

16. The combination with a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means for restraining each of said contact members in normal position, tripping mechanism for disengaging said contact members from said restraining means, means for alternately actuating said contact members to normal position and allowing their free movement after release from said restraining means comprising an oscillatory member concentric with which said links are pivoted, and shoulders on said oscillatory member for engagin said links for actuating them in opposite directions.

17. The combination with a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means for restraining each of said contact members in normal position, tripping mechanism for disengaging said contact members from said restraining means, means for alternately actuating said contact members to normal position comprising a shaft upon which said links are pivoted, and a tubular member enclosing said shaft and having slots into which said links extend. said slots having such arcuate lengths and so disposed angularly with respect to each other that upon operation of said tripping mechanism said links partake of rotary movement independently of said tubular member, said tubular member engaging at one end of each of said slots with a link for actuating the same to move said contact members to normal osition.

18. The combination wit .a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means for restraining each of said contact members in normal position,tripping mechanism for disengaging said contact members from said restraining means, means for alternately actuating said contact members to normal position comprising a shaft upon which said links are )ivoted, a tubular member enclosing said sha t and having slots into which said links extend, said slots having such arcuate lengths and so disposed angularly with respect to each other upon operation of said tripping mechanism said links partake of rotary movement independently of said tubular member, said tubular member engaging at one end of each of said slots with a link for actuatin the same to move said contact members to normal position, and means biased toward normal position for rocking said shaft in opposite directions.

19. The combination with a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means for restraining each of said contact members in normal position, tripping mechanism for disengaging said contact members from'said restraining means, means for alternately actuating said contact members to normal position comprising a shaft upon which said links extend, said slots having such arcuate lengths and so disposed angularlv with respect to each other that upon operation of said tripping mechanism said links partake of rotary movement independently of said tubular member, said tubular member engaging at one end of each of said slots with a link for actuating the same to move said contact members to normal position, an enclosing housing, and means external thereto for rocking said shaft in opposite directions.

20. The combination with a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means for restraining each of said contact members in normal position, tripping mechanism for disengaging said contact members from said restraining means, means for alternately actuating said contact members to normal position comprising a shaft upon which said links are pivoted, a tubular member enclosing said shaft and havin slots into which said links extend, said s ots having such arcuate lengths and so disposed angularly with respect to each other that upon operation of said tripping mechanism said links partake of rotary movement independently of said tubular member, said tubular member engaging at one end of each of said slots with a link for actuating the same to move said contact members to normal position, an enclosing housing, and means external thereto biased toward normal position for rocking said shaft in opposite directions.

21. The combination with an electric switch having a contact member movable to and from normal position, of actuating means therefor, an enclosing housing. a movable door therefor having an aperture, an indicating member within said housing slidable on said door and visible through said aperture, said indicating member having a projection extending into the path of travel of a member movable with said contact member for sliding said indicating member on said door, and a spring opposing movement of said indicating member by said member movable with said contact member.

22. The combination with an electric switch having a contact member movable to and from normal position, of actuating means therefor, an enclosing housing, a movable door therefor having an aperture. an indicating member slidable on said door and visible through said aperture, means biasing said indicating member toward one indicating position, and a projection on said indicating member extending into the path of travel of the member movable with said contact member and actuated thereby from normal indicating position. 1

23. The combination with an electric switch having a contact member movable to and from normal position, of actuating means therefor, an enclosing housing, a movable door therefor having an aperture, an indicating member slidable on said door and visible through said aperture, means biasing said indicating member toward one indicating position, and a projection on said indicating member extending into the path of travel of the member movable with said contact member and actuated thereby from normal indicating position, said member movable with said contact member when in predetermined position being in the path of travel of said projection when moving with said door to prevent closure thereof.

24. The combination with a movable member of a switch, of actuating mechanism therefor comprising a link pivoted to said member, a second link pivoted to said first named link, said links having lost motion with respect to each other. and a rotary member having lost motion with respect to said second link for actuating the same.

25. The combination with a movable member of a switch, of actuating mechanism therefor comprising a link pivoted to said member. a second link pivoted to said first named link, said links having lost motion with respect to each other, a rotary member having lost motion with respect to said second link for actuating the same, an enclosing housing. and means external thereto for actuating said rotary member.

26. The combination with a movable member of a switch. of actuating mechanism therefor comprising links. a member for actuating one of said links and through another of said links actuating said movable member. said links forming a lost motion connection between said actuating member and said movable member. an enclosing housing. and means external thereto for. operating said actuating member.

27. The combination with a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means movable in opposite directions for actuating said links, an enclosing housing, and means external thereto for operating said actuating means.

28. The combination with a plurality of switches each comprising a movable contact member, links movable in opposite directions for actuating said contact members in similar directions, means movable in oppo- I site directions for actuating said links, an enclosing housing, and means external thereto for operating said actuating means. said links forming lost motion connections between said actuating members and the movable contact members of said switches. 29. The combination. with a movable member of a switch, of oscillatory link structure connected therewith, and a rotatable slotted member into and within which said link structure extends and is pivoted, said member engaging at the end of its slot with said link structure for actuating the same, said link structure forming a lost motion connection between said rotatable member and said movable switch member.

30. The combination with a movable contact member of a switch, of oscillatory link structure connected therewith, and a rotatable slotted member into which said link structure extends, said link structure having lost motion with respect to said rotatable member.

31. The combination with a circuit breaker comprising a movable contact member, actuating mechanism therefor, and automatic tripping mechanism therefor. of housing structure, a member distinct from said contact member carried by said housing structure and movable thereon, said member moved from one position to another by said actuating mechanism, and means returning said riiember when free of said actuating mechanism to position in which said member will encounter obstruction preventing movement of said housing structure in predetermined direction.

32. The combination with a circuit breaker comprising a movable contact member, actuating mechanism therefor, and automatic tripping mechanism therefor, of housing structure, a member distinct from said contact member carried by said housing structure and movable thereon, an indicator movable therewith, said member moved from one position to another by said actuating mechanism, and means returning said member when free of said actuating mechanism to position in which said member will encounter obstruction preventing movement of said housing structure in predetermined direction.

33. The combination with a ,circuit breaker comprising a movable contact member, actuating mechanism therefor, and automatic tripping mechanism therefor, of housing structure, a member distinct from said contact member carried b said housing structure and movable thereon, said member moved from one position to another by said actuating mechanism, and means returning said member when free of said actuating mechanism to position in which said member will encounter said actuating mechanism to prevent movement of said housing structure in predetermined direction.

34. The combination with a circuit breaker comprising a movable contact member, actuating mechanism therefor, and automatic tripping mechanism therefor, of housing structure, a member distinct from said contact member carried by said hous ing structure and movable thereon, an indi cator movable therewith, said member moved from one position to another by said actuating mechanism, and means returning said member when free of said actuating mechanism to position in vwhich said member will encounter said actuating mechanism to prevent movement of said housing structure in predetermined direction.

35. The combination with a circuit breaker comprising a movable contact member, actuating mechanism therefor, and automatic tripping mechanism therefor, of housing structure therefor having-a movable wall, a member distinct from said contact member carried by said wall and movable thereon by said actuating mechanism, and means for returning said member to position in which it will meet obstruction preventing movement of said movable wall in predetermined direction.

36. The combination with a circuit breaker comprising a movable contact member, actuating mechanism therefor, and automatic tripping mechanism therefor, of housing structure therefor having a movable Wall, a member distinct from said contact member carried by said wall and movable thereon by said actuating mechanism, and means for returning said member when free of said actuating mechanism to position where it will be obstructed by said actuating mechanism to prevent movement of said movable wall in predetermined direction.

37 The combination with an electric switch having a contact member movable to and from normal position, of actuating mechanism therefor, an enclosing housing having a movable wall, an indicating member slidable on said wall, means biasing said indicating member toward one position, a projection on said indicating member detached from said actuating mechanism and extending into the pathof travel thereof and actuated thereby to move said indicating member to a difi'erent position, and means returning said projection to position with respect to said actuating mechanism in which said projection obstructs movement of said wall in predetermined direction.

38. The combination with an electric switch having a contact member movable to and from normal position, of actuating mechanism therefor, a support movable with respect to said actuating mechanism, a member slidable on said support, means biasing said slidable member toward one position, a projection on said slidable member detached from and extending into the path of travel of said actuating mechanism and actuated thereby to a different position, said biasing means returning said projection to said one position when free of said actuating'mechanism, said projection obstructing movement of said support toward said actuating mechanism when said slidable member has been returned to said one position.

39. The combination with an electric switch comprising a movable contact member and a toggle for actuating the same, of housing structure movable toward and away from operative position with respect to said contact member and toggle, a member carried by said housing structure and movable thereon in one direction by said toggle, and means for returning said member when free of said toggle to position in which said member will encounter said toggle and thereby prevent movement of said housing, structure in predetermined direction.

40. The combination with the movable member of a switch, of actuating mechanism therefor comprising a rotatable tubu- -lar member having a slot, a shaft within said tubular member, and a switch-actuating member actuated by said tubular member extending into said slot and pivoted upon said shaft therein, said slot having extent permit ting lost motion between said tubular member and said switch-actuating member.

In testimony whereof I have hereunto affixed my signature this 24th day of November, 1919.

VILLIAM M. SFOTT. 

